my marshall has way to much treble.

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by MattCrane, Jun 11, 2005.

  1. MattCrane

    MattCrane Member

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    I have a Marshall jmp mk2. i took two tubes out run it at 50 watts@ 8 ohms through a 16 ohms cab. Would that have any effect on the treble? It is super trebly I have to turn the treble down all the way. Thanks.
     
  2. Neil

    Neil Member

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    I had a 2203 100 watt head (about a 1984 model). I used a Marshall 4x12 with vintage 30s. At low volume settings (but not actually low volume!) it was painfully thin and trebley. I tried different gain preamps tubes and different brand power amp tubes to try and tame it. There is a web page some where that shows in detail how to tame these amps. I made those changes and they helped. The only thing that really worked (I found out by accident) was to turn it up close to full. Sounded good but was unusable. I tried a powerbrake but they dont really reduce the volume by much before they start to affect the sound.

    I sold it in the end after I compared it to a Bogner Shiva combo. I got the Shiva, imho better in every way unless you can crank the Marshall and then it is a one trick pony.

    Just my experience. Others may differ

    neil
     
  3. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    I routinely turn the treble on my Marshall flavored amps off or nearly off. Never do they get above 3-4 on treble, and usually the bass and mids are bumped up well over the treble knob level.
     
  4. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    I routinely turn the treble on my Marshall flavored amps off or nearly off. Never do they get above 3-4 on treble, and usually the bass and mids are bumped up well over the treble knob level.

    If you have an overly trebly amp, try darker speakers with it (55 hz models) that will tame alot of the highs.

    How do you have your amp controls set, what guitar, and what pickups do you use?
     
  5. LaXu

    LaXu Member

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    I find turning presence all the way down or very low is the best way to tame 'em. Takes the fizz out of the sound.

    The 18W handwired combos on the other hand don't seem to be overly trebly. Rather pleasing tones at ear-friendly volumes.
     
  6. bruce egnater

    bruce egnater Member

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    That extreme high end in Marshalls (especially non/master volume models) is caused buy one little capacitor that is wired across two terminal of the gain pot. It is sort of a traditional Marshall thing so for some reason they continue to do it to this day. That is why the amps have the horrible high end until you get the gain knob past about 2:00 and suddenly the low end comes in. That capacitor is basically how many amps do their bright switches, but the Marshall capacitor is about 10 times the value (hence 10 times the high end boost) of other amps. Unfortunately, the amp is deafening at that setting. You can cut out (or reduce) the value of that capacitor and vastly improve things.
     
  7. MattCrane

    MattCrane Member

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    yeah its a resisitor on the volume pot right?Im gonna snap it one of these days.
     
  8. bruce egnater

    bruce egnater Member

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  9. MattCrane

    MattCrane Member

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  10. sparkle**

    sparkle** Member

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    Cut the bright cap...Also is it a master or non master? If non are you jumping channels?
     
  11. MattCrane

    MattCrane Member

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    its only two inputs. It has a volume and gain knob.
     
  12. bruce egnater

    bruce egnater Member

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    Didn't realize it was a MV model. Where do you set the "gain" knob. If you have it near full up, cutting out the capacitor will not do anything. Will need to do other stuff.

    egnater
     
  13. MattCrane

    MattCrane Member

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    I keep it at 2 o clock. the volume around 10 or 11 o clock.
     
  14. bruce egnater

    bruce egnater Member

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  15. MattCrane

    MattCrane Member

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    Ok I will.
    [​IMG]
    Im assuming its the one on the pot right there?
     
  16. MattCrane

    MattCrane Member

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    I miss that little thing. It soudns much more modern now.
     
  17. MattCrane

    MattCrane Member

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    I'm definately gonna solder it back on.
     
  18. JerryP

    JerryP Member

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    If your filter caps are old or original that can cause the amp to be bright and lacking in low end.
    Jerry
     
  19. MattCrane

    MattCrane Member

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    Well im gonna buy a new cab. I mgith get vintage 30s or green backs. it feels like when i cut the capacitor. It was more sterile lost its shimmer the little bit of edge.
     
  20. TheAmpNerd

    TheAmpNerd Member

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    These can be really kewl amps.

    If you don't want it so thin up front
    you can change the .68 bypass cap
    to another value.

    Try a 10uf - 25uf cap for fuller sound.

    You can also add a 100K resistor
    to the wiper (middle) of the master
    volume to improve the tone a queiter
    levels. This is the simple method.
    See TUT, Vol 3 of the final fix.

    But that should help some.

    These amps can be awsome.

    One customer wanted was earlier break up.

    So, I take time to really dial it in, add gain
    so he gets earlier break up, and I'm
    real careful to get the hum out, etc.

    Get the amp all stablized,
    and know it it is the ****.

    He trys it out, pays for it etc.

    I get a call and he comes back the next
    day yelling....

    The amp feeds back with everything on 10.
    It shouldn't do that, fix it. I test all my amps
    this way.


    So I reversed all the wonderful stuff I did.
    The amp is only half of what is was.

    But, now he is happy (I guess).

    Moral of the story...

    If you want earlier break up,
    then don't put everything on 10
    and whine about it.

    It still pisses me off, damn that amp sounded good.

    enjoy. Oh and as most folks have suggested
    put in new filters, you'll be glad you did.
     

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